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  1. #1
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    Incy Wincy Spider...

    Jezza Bear was kicking his heels at the weekend as he couldn't get into the Lounge <img src=/S/innocent.gif border=0 alt=innocent width=20 height=20> he was staring at the clock on the mantelpiece thinking he should do some house work as there was a lot of dust and cobwebs around when at exactly six o'clock, he saw a spider start to walk at a constant speed from the hour hand anticlockwise round the edge of the clock's face. It finally reached the minute hand, turned around (instantaneously) and walked in a clockwise direction at the same constant speed.


    The spider reached the minute hand again after 20 minutes.


    Jezza Bear wants to know what was the time when the spider met the minute hand the second time?
    Jerry

  2. #2
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    Re: Incy Wincy Spider...

    <span style="background-color: #FFFF00; color: #FFFF00; font-weight: bold">Since the spider started its walk at exactly six o'clock and walked for 20 minutes in total, then he must have arrived at 6.20.</span hide>?
    <font color=blue><font face="Script MT Bold"><big>Rob</big></font face=script></font color=blue>

  3. #3
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    Re: Incy Wincy Spider...

    <span style="background-color: #FFFF00; color: #FFFF00; font-weight: bold">6:32 - on the basis he was walking at '240 minutes' per hour</span hide>

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    Re: Incy Wincy Spider...

    <img src=/S/nope.gif border=0 alt=nope width=15 height=15> The spider was walking for more than 20 minutes in total. The journey was in two sections: (1) hour hand to minute hand, and (2) minute hand to minute hand again. The second part of the journey took 20 minutes, so the overall journey time must have been longer.
    Waggers
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  5. #5
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    Re: Incy Wincy Spider...

    Rob, <img src=/S/hmmn.gif border=0 alt=hmmn width=15 height=15> <span style="background-color: #FFFF00; color: #FFFF00; font-weight: bold">The clock is working and the minutes and hour hands will be moving while Incy Wincy is walking!!!!!!!!!!!</span hide>
    Jerry

  6. #6
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    Re: Incy Wincy Spider...

    <span style="background-color: #FFFF00; color: #FFFF00; font-weight: bold">6:26

    Denote the speed of the minute hand by Vm and that of the spider by Vs (in degrees/minute). We know that Vm = 6 (360 degrees in 60 minutes).
    In 20 minutes, the spider covers 360 degrees more than the minute hand, so 360/(Vs-Vm) = 20. From this we deduce that 360 = 20Vs-120, hence Vs = 24.
    The time of the first part is 180/(Vm+Vs) = 180/30 = 6 minutes. The total time is 6 + 20 = 26 minutes, so it is 6:26 when the spider meets the minute hand the second time.</span hide>

  7. #7
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    Re: Incy Wincy Spider...

    I concur....Have a [choccy bar]
    Jerry

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    Re: Incy Wincy Spider...

    Sorry, Jezza. I misinterpreted the question.
    <font color=blue><font face="Script MT Bold"><big>Rob</big></font face=script></font color=blue>

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